7QSO

Bovine complex I in lipid nanodisc, State 3 (Slack)

Summary for 7QSO

• Entry DOI: 10.2210/pdb7qso/pdb
• EMDB information: 14132 14133 14134 14139 14140
• Descriptor: NADH-ubiquinone oxidoreductase chain 3, NADH-ubiquinone oxidoreductase chain 6, NADH-ubiquinone oxidoreductase chain 4L, ... (59 entities in total)
• Functional Keywords: mitochondrial complex i, respiratory complex i, nadh:ubiquinone oxidoreductase, nanodisc, electron transport
• Biological source: Bos taurus (cattle); More
• Total number of polymer chains: 45
• Total formula weight: 1075898.58

Authors

Chung, I.,Bridges, H.R.,Hirst, J. (deposition date: 2022-01-13, release date: 2022-05-25, Last modification date: 2022-09-28)

Primary citation

Chung, I.,Wright, J.J.,Bridges, H.R.,Ivanov, B.S.,Biner, O.,Pereira, C.S.,Arantes, G.M.,Hirst, J.
Cryo-EM structures define ubiquinone-10 binding to mitochondrial complex I and conformational transitions accompanying Q-site occupancy.
Nat Commun, 13:2758-2758, 2022

PubMed Abstract: Mitochondrial complex I is a central metabolic enzyme that uses the reducing potential of NADH to reduce ubiquinone-10 (Q) and drive four protons across the inner mitochondrial membrane, powering oxidative phosphorylation. Although many complex I structures are now available, the mechanisms of Q reduction and energy transduction remain controversial. Here, we reconstitute mammalian complex I into phospholipid nanodiscs with exogenous Q. Using cryo-EM, we reveal a Q molecule occupying the full length of the Q-binding site in the 'active' (ready-to-go) resting state together with a matching substrate-free structure, and apply molecular dynamics simulations to propose how the charge states of key residues influence the Q binding pose. By comparing ligand-bound and ligand-free forms of the 'deactive' resting state (that require reactivating to catalyse), we begin to define how substrate binding restructures the deactive Q-binding site, providing insights into its physiological and mechanistic relevance.

PubMed: 35589726
DOI: 10.1038/s41467-022-30506-1

Experimental method

ELECTRON MICROSCOPY (3.02 Å)